Dementia of the Alzheimer's Type (DAT) is characterizd by progressive cognitive/behavioral impairment. As DAT progresses the patient is less able to care for him/herself, becoming more dependent on his/her caregiver (usually spouse). Over time the patient becomes more restricted to the home environment and the psychosocial environment of the caregiver/spouse. As such, the patient's functioning may increasingly reflect the functioning of his/her spouse. Simultaneously, via feedback loops, increased cognitive/behavioral decline in the patient may result in increased psychosocial impairment in the spouse. This vicious cycle may lead to patient decline well beyond that due to neuronal degeneration. Unfortunately, much needs to be learned about these dynamics: The vast majority of DAT research has concentrated on the patient or the caregiver, but not on both. In this study longitudinal relationships will be examined to assess the importance of spouse variables on mild DAT patients (Aim 1) and mild DAT patient variables on spouses (Aim 2): 1) Do initial and/or follow-up psychosocial spouse variables account for variance in follow-up cognitive/behavioral functioning of patients beyond that expected from initial cognitive/behavioral functioning of patients? 2) Does initial and/or follow-up cognitive/behavioral functioning of patients account for variance in follow-up psychosocial spouse variables beyond that expected from initial psychosocial spouse variables? A two wave follow-up design will be used: patients/spouses will be first assessed at entry into the Geriatric and Family Services Clinic. Follow-up assessments will be performed 18 months after the respective initial assessments. Criteria for patient inclusion will be: DSM III diagnosis of Primary Degenerative Dementia (no mixed dementias), mild (early) stage of AD, living with one's spouse who is the caregiver, and living within one hour's drive of Seattle. Given these 4 criteria initial/follow-up data will be obtained on 90 dyads. Hierarchical regression will be used to meet the aims. Variables entered will reflect a theoretical model of stress/distress which involves stressors, resources, vulnerability and distress. This research will shed light on two ADAMHA priorities: The interaction of family stress, coping and the management of DAT, and factors in the psychosocial environment that shape and maintain positive behavior in DAT patients.